Ag Sputtering Research Articles

Enhanced Surface Plasmon by Clusters in TiO2-Ag Composite.

The surface plasmon in the composite composed of the noble metals and the semiconductors is interesting because of the various charges and the potential applications in many fields. Based on a highly ordered 2D polystyrene spheres array, the ordered composite nanocap arrays composed of TiO2 and Ag were prepared by the co-sputtering technique, and the surface morphology was tuned by changing TiO2 sputtering power. When TiO2 sputtering power was 60 W and Ag sputtering power was 10 W, the composite unit arrays showed the nanocap shapes decorated by many composite clusters around. The composite clusters led to the additional local coupling of the electromagnetic fields and significant Surface-Enhanced Raman Scattering (SERS) observations, which was also confirmed by the finite-different time-domain simulation. The SERS-active substrate composed of the composite nanocaps decorated by clusters realized the accurate detection of the thiram with concentrations down to 10-9 M.

Realization of ZnO microrods and Ag nanoparticles on glass and Si substrates by magnetron sputtering and near band edge photoluminescence enhancement from the exciton-plasmon system

• A dry method of fabrication of Ag nanoparticles and ZnO microrods heterostructure. • Preferential nucleation of Ag nanoparticles in proximities of ZnO microrods. • Seed assisted growth of ZnO microrods at higher gas pressure and shorter duration. • Near-UV (380 nm) emission enhancement possibly due to exciton-plasmon interaction. • Nearly 3-fold enhancement of near band edge photoluminescence from ZnO microrods. This work presents a physical vapour-based fabrication of an exciton-plasmon system via depositions of ZnO microrods (ZnOµRs) and Ag nanoparticles (AgNPs) on glass and p-type Si substrates. Pulsed DC sputtering of ZnO at a relatively higher Ar pressure and varying applied power enables deposition of ZnOµRs on ZnO seed layers. Sputtering of Ag ensures fabrication of AgNP/ZnOμR heterostructure with good adhesion suitable for device realization. Microstructural analyses confirm formations of wurtzite ZnOμRs and f.c.c. AgNPs. AgNPs are observed as isolated clusters due to preferential nucleation in the proximities of ZnOµRs. UV-Vis absorption spectroscopy reveals broad surface plasmon resonance (SPR) of Ag NPs around 538 nm, which experiences a bathochromic shift in AgNP/ZnOμR heterostructure. The photoluminescence (PL) spectra of AgNP/ZnOμR heterostructure suggest a 3-fold enhancement of narrow near band edge (NBE) emission attributed to the exciton-plasmon interaction.

Structural Evolution of Bulk Silver during Cold Rolling and Annealing

Sputtering target is commonly used in semiconductor manufacturing for the preparation of thin films. Cold rolling and annealing treatment of bulk Ag is the routine process to prepare Ag sputtering target. In this paper, the microstructure evolution of Ag after cold rolling and annealing treatment was studied, and the results showed that annealing temperature affects the recrystallized structure of Ag and that 600 °C/1 h treatment can achieve complete recrystallization. At the same time, the texture evolution was also observed and discussed.

Ultra-flexible and transparent electrodes with controllable crack length via metal–polymer hybrid nanostructure

• A method for fabricating a super-flexible transparent electrode. • The flexible electrodes exhibited excellent flexibility. • Under severe cyclic folding fatigue a peak strain of 2.5% was observed. • A folding-cycle count of 100,000 was obtained. • The good performance was due to the metal–polymer hybrid nanostructure. We propose a method for improving the flexibility of transparent electrodes through a mechanism that effectively reduces the crack length under cyclic folding fatigue. Our proposed method is based on the use of a metal–polymer hybrid (MPH) nanostructure composed of indium tin oxide (ITO), Ag, and a fluoropolymer, which are commercially available materials widely used in the display-panel manufacturing industry. For flexible electrodes wherein the MPH nanostructure was adjusted using Ag sputtering powers within the range of 20–50 W, the changes in the resistance after 100,000 folding cycles with a peak strain of 2.5% were 4.57–17.9%, whereas those in the case of the ITO/Ag/ITO (IAI) thin-film electrode, i.e., without the MPH nanostructure, increased dramatically to 11,228%. Through the introduction of the MPH nanostructure, the crack length was significantly reduced to 8.76–88.1 μm compared to that of the IAI thin-film electrode (> 945 μm), and also became controllable through the adjustment of the number density of the MPH nanostructure.

Conductive Micro-Paths for Current Sharing Between REBCO Tapes in High-T c Superconducting Conductors to Improve Stability

The REBa <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Cu <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">_y</i> (REBCO, RE: Rare Earth) is expected to be applied to fusion magnets, and various REBCO conductors with a high current capacity has been developed for the fusion magnets by stacking the REBCO tapes. A disadvantage of REBCO conductors is that the buffer layer prevents current sharing between the tapes, reducing conductor stability. In this study, we propose conductive micro-paths where the current is shared between the REBCO tapes in order to improve the stability of conductors. We fabricated the conductive micro-paths in REBCO tapes by using a UV pulsed laser and an Ag sputtering method, and evaluated them. Furthermore, we investigated the current sharing between tapes at 77 K with two REBCO tapes with conductive micro-paths. As a result, in REBCO tapes with conductive micro-paths, the current was shared through these paths between the REBCO tapes at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$1.1 &lt; I/{I_{\bf{c}}} &lt; 1.15$</tex-math></inline-formula> and was successfully bypassed the damaged area.

Ag sputtering–assisted phase formation of Ag2S‐decorated ZnS composite sheets and their photoactive performances

AbstractThe Ag2S crystallites–decorated ZnS composite sheets were synthesized by combinational methodology. Two types of ZnS sheet templates were obtained through the vulcanization of ZnO sheets with sulfur precursors of thiourea and Na2S, and then ZnS–Ag2S heterogeneous sheets were obtained with sputtering Ag crystallites and post‐annealing procedures. The ZnS sheets have rugged and smooth surfaces formed with sulfur precursors of thiourea and Na2S, respectively. Both the initial microstructures of ZnS sheet templates and Ag2S decoration content affect the photoactivity of the ZnS–Ag2S composite sheets. Compared with the pristine ZnS, the ZnS–Ag2S composite sheets with a suitable Ag2S loading content (Ag at% = 3.6–3.8) are beneficial to improve the photoactivity, which could be explained by the combination of narrow bandgap; Ag2S crystallites would enhance photon absorption and separation efficiency of photoinduced charge carriers. The scavenger tests and photodegradation mechanism show that hydroxyl radicals and holes were the main active species for the ZnS–Ag2S composite sheets to photodegrade methyl orange solution. The experimental results herein provide a novel synthesis approach to decorate Ag2S crystallites onto ZnS with tunable contents and present important design guidelines for the resultant ZnS–Ag2S composite sheets to demonstrate marked improvement in photoactivity.

Evaporating and Sputtering of High-Density Ag Nanotwinned Films on GaAs Compound Semiconductor Wafers

Evaporating and Sputtering of High-Density Ag Nanotwinned Films on GaAs Compound Semiconductor Wafers

Fabrication and performances of silver grid transparent conducting films and heaters on glass and PET substrates based on fractal periodic grid pattern design

A metal grid transparent conducting film (TCF) requires an excellent trade-off between optical transparency and electrical conductivity, both of which are affected by grid patterns and parameters. In this work, the fractal geometry was introduced to design fractal periodic grid patterns, which were employed to fabricate fractal periodic Ag grid TCFs with different grid periods, pitches and thicknesses on glass substrates by magnetron sputtering Ag films and laser localized removal. By comparing with the corresponding conventional periodic Ag grid, the fractal periodic Ag grid was confirmed to enable a significant improvement in trade-off between optical transparency and electrical conductivity, and thus excellently improving the comprehensive properties of the TCFs. The optimal fractal periodic Ag grid TCF achieved a figure of merit of 15.04 × 10–2 Ω–1, which was higher than that of the optimal conventional periodic Ag grid TCF (11.38 × 10–2 Ω–1). In addition, transparent heaters were prepared by using the optimal fractal periodic Ag grid TCFs on glass and flexible PET substrates, and showed excellent heating performances, good performance stability and deicing availability. This work provides a simple and extendable method for tailoring optical transmittance and electrical conductivity to fabricate high-performance TCFs.

Superhydrophobic Ag‐Decorated CuO Nanowire Arrays with Analyte‐Concentrating and Self‐Cleaning Binary Functions for Ultrasensitive and Recyclable Surface‐Enhanced Raman Scattering

AbstractSurface‐enhanced Raman scattering (SERS) is considered a promising analytical technique for the detection of analytes. Considering the practical SERS detection, it is necessary to develop low‐cost, highly sensitive, and recyclable SERS‐active substrates. Here, a simple and flexible approach is proposed to fabricate a superhydrophobic Ag‐decorated CuO (named as CuO@Ag) nanowire array substrate with analyte‐concentrating and self‐cleaning binary functions for ultrasensitive and recyclable SERS detection. During this process, a superhydrophobic CuO@Ag nanowire array is made via fabrication of a CuO nanowire array by oxidizing and calcinating an ordered porous anodic aluminum oxide template on Cu foil, and following with Ag sputtering deposition on CuO nanowire array. Remarkably, this SERS substrate exhibits ultrasensitive SERS detection ability attributed to superhydrophobic plasmonic metal nanostructured arrays with high analyte‐concentrating ability and excellent photocatalytic capability due to this metal‐semiconductor composite nanostructure. These advantageous properties allow for SERS detection of malachite green with a limit of detection of 6.73 × 10−13 m and self‐cleaning via photodegradation of adsorbed analytes with visible‐light illumination. Consequently, it achieves recyclable SERS detection. This research demonstrates a simple and flexible approach for fabricating recyclable SERS‐active substrate, which expands the practical SERS applications in chemical and biological analysis, food safety, and healthcare.

Fabrication of highly sensitive and uniform Ag/PS/PDMS SERS substrate and its application for in-situ detection

In this study, we developed a flexible and transparent silver/polystyrene/polydimethylsiloxane (Ag/PS/PDMS) substrate with both high density of hot spots and satisfactory uniformity using a cost-effective approach. Via template-guided self-assembly, PS beads were arranged regularly in nanobowls of a square array on PDMS, whose surface structure was transferred from a commercial complementary metal oxide semiconductor chip. Roughness was introduced onto the PS bead surface by nitrogen plasma treatment, followed by sputtering of Ag which generated many hot spots. Differential roughness on the PS bead surface greatly influenced the morphology of the Ag/PS/PDMS substrate. A meat-ball like surface structure was formed with a plasma etching time of 5 min, whose growth mechanism was proposed based on the scanning electron microscope analysis. The high sensitivity and desirable uniformity of the meat-ball like Ag/PS/PDMS substrate were demonstrated by using crystal violet as a Raman reporter, exhibiting an enhancement factor of 2.7 × 107 and a relative standard deviation of 5.04%. Thiram of a lower concentration than the maximum residue limit on the cucumber surface could easily be detected in situ by the proposed substrate, demonstrating its great potential for in-situ food safety analysis.

Role of Ag and Cu as an interfacial layer on the electrochemical performance of Ni/Ag/ Co3(PO4)2 and Ni/Cu/Co3(PO4)2 electrodes for hybrid energy storage devices

Hybrid energy storage devices unifying the effect of both batteries (high specific energy) and capacitors (high specific power) have emerged in recent years due to their admirable cyclic stability and charge storage capability. Considerable amount of research has been conducted to optimize the electrode materials capable of showing good electrochemical characteristics. Here, we report the influence of interfacial layer of Ag and Cu on the electrochemical performance of cobalt phosphate electrode. Sputtering of Ag and Cu has been amalgamated to improve the interfacial properties of the current collector. After initial structural and morphological study, detailed electrochemical characterizations have been employed for Ni/Ag/Co3(PO4)2 and Ni/Cu/Co3(PO4)2 have been investigated by utilizing various characterizations. Hybrid device was fabricated using the combination Ni/Ag/Co3(PO4)2 since, Ag possess impressive electrochemical characteristics and electrical conductivity. The fabricated device has achieved the energy density of 65.8 Whkg−1 and power density of 6012 Wkg-1 along with the 85.6% retention after 1000 GCD cycles showing the device is stable enough. These results make the hybrid device a potential candidate for supercapattery applications.

초경량 PEMFC용 폴리머 분리판 집전 방식 연구

In this study, polymer bipolar plates for ultra-light polymer electrolyte membrane fuel cells (PEMFCs) were fabricated. Various methods for current collecting were applied to ensure electron conductivity of the polymer bipolar plates. Direct wire contact and Ag sputter process were applied. The Ag current collecting layer fabricated by the sputter process showed a well-covered and defectless surface. After preparations of bipolar plates, the effects of current collecting methods of bipolar plates on the electrochemical properties of PEMFCs were systematically investigated. The maximum power density of PEMFCs with the Ag current collecting of layered polymer bipolar plates decreased 37.39% because of increased ohmic resistance. However, the power/weight of PEMFCs with the Ag current collecting of layered polymer bipolar plates increased 27.23% because of the dramatically reduced weight (-50.63%) of bipolar plates compared to the graphite bipolar plates. We affirm that results in this report can provide meaningful insight for portable electrochemical energy devices.

Vacuum Brazing of Metallized YSZ and Crofer Alloy Using 72Ag-28Cu Filler Foil.

The study focused on dissimilar brazing of metallized YSZ (Yttria-Stabilized Zirconia) and Crofer alloy using BAg-8 (72Ag-28Cu, wt%) filler foil. The YSZ substrate was metallized by sequentially sputtering Ti (0.5/1 μm), Cu (1/3 μm), and Ag (1.5/5 μm) layers, and the Crofer substrate was coated with Ag layers with a thickness of 1.5 and 5 μm, respectively. The BAg-8 filler demonstrated excellent wettability on both metallized YSZ and Crofer substrates. The brazed joint primarily consisted of Ag-Cu eutectic. The metallized Ti layer dissolved into the braze melt, and the Ti preferentially reacted with YSZ and Fe from the Crofer substrate. The globular Fe2Ti intermetallic compound was observed on the YSZ side of the joint. The interfacial reaction of Ti was increased when the thickness of the metallized Ti layer was increased from 0.5 to 1 μm. Both brazed joints were crack free, and no pressure drop was detected after testing at room temperature for 24 h. In the YSZ/Ti(0.5μ)/Cu(1μ)/Ag(1.5μ)/BAg-8(50μ)/Ag(1.5μ)/Crofer joint tested at 600 °C, the pressure of helium decreased from 2.01 to 1.91 psig. In contrast, the helium pressure of the YSZ/Ti(1μ)/Cu(3μ)/Ag(5μ)/BAg-8(50μ)/Ag(5μ)/Crofer joint slightly decreased from 2.02 to 1.98 psig during the cooling cycle of the test. The greater interfacial reaction between the metallized YSZ and BAg-8 filler due to the thicker metallized Ti layer on the YSZ substrate was responsible for the improved gas-tight performance of the joint.

SERS study of wheat leaves substrates with two different structures

Wheat leaf is a natural material having abundant gaps between micro-protrusions and flat structures. Magnetron sputtering method is used to sputter Ag film on wheat leaves and Rhodamine 6G (R6G) is used to detect the SERS difference caused by different structures of the same material. The SERS signal shows that the Raman intensity of the micro-protrusions is stronger than that of the flat parts. The results shows that there are more gaps in the protrusion structure per unit area, thereby providing more “hot spots”, which plays an important role in improving the SERS signal. Therefore, this low-cost and high-performance SERS system shows excellent application prospects and provides a new idea to improve SERS signal by using natural biomaterials as SERS substrate.

Self-driven heterostructure photodetector of sputtered CZTS film on c-Si with an inverted pyramid structure

Ag has been incorporated into the CZTS film through post-doping by magnetron sputtering to decrease the CuZn anti-site defect. Efforts have been dedicated to optimize the Ag sputtering time and 60 s will be the best as surveyed from the SEM, XRD and Raman spectra. Then the broad-band self-driven heterostructure photodetector has been manufactured by combining the CZTS and inverted pyramid n-Si (IP n-Si). The device represents the first-rank property under the irradiation of 5 mW, 780 nm LED with 0 V bias with the responsivity and detectivity of 7.2 mA/W and 4.98 × 1010 Jones respectively. The device can persist excellent linearity when enduring a 40 mW-80 mW, 980 nm NIR laser with 0 V bias. The comprehensive performance becomes the best under the irradiation of a 50 mW laser. The responsivity and detectivity are 1.22 mA/W and 1.98 × 1010 Jones. The device can also work stably as the laser changes from 1 Hz to 15 kHz. The rise time and decay time are 93.3 μs and 141.0 μs respectively. These results open up an innovative application for CZTS to build a broad-band self-driven photodetector as a window-layer.

The Sputtering Performance of Ag Sputtering Targets with Different Microstructure

The Sputtering Performance of Ag Sputtering Targets with Different Microstructure

Ag Nanoislands Modified Carbon Fiber Nanostructure: A Versatile and Ultrasensitive Surface-Enhanced Raman Scattering Platform for Antiepileptic Drug Detection

A high-efficiency surface-enhanced Raman scattering (SERS) detection method with ultra-high sensitivity has been widely applied in drug component detection to optimize the product quality verification standards. Herein, a controllable strategy of sputtering Ag nanoislands on carbon fiber (C-fiber) via magnetron sputtering technology was proposed to fabricate a versatile Ag-C-fiber SERS active substrate. A wide range of multi-level electromagnetic enhancement “hot spots” distributed on Ag-C-fiber nanostructures can efficiently amplify Raman signals and the experimental enhancement factor (EEF) value was 3.871 × 106. Furthermore, substantial “hot spots” of large-scale distribution guaranteed the superior reproducibility of Raman signal with relative standard deviation (RSD) values less than 12.97%. Limit of detection (LOD) results indicated that when crystal violet (CV) is employed as probe molecule, the LOD was located at 1 × 10−13 M. By virtue of ultra-sensitivity and good flexibility of the Ag-C-fiber nanotemplate, Raman signals of two kinds of antiepileptic drugs called levetiracetam and sodium valproate were successfully obtained using an SERS-based spectral method. The Ag-C-fiber SERS detection platform demonstrated a good linear response (R2 = 0.97486) in sensing sodium valproate concentrations in the range of 1 × 103 ng/μL−1–1 ng/μL. We believe that this reliable strategy has potential application for trace detection and rapid screening of antiepileptic drugs in the clinic.

Modified Ag nanoparticles on the regular array structure to improve the optical properties

The surface-enhanced Raman scattering (SERS) technique strongly depended on the excellent optical properties of the substrate. However, simply roughing of the metal surfaces to support SERS techniques suffer from the lack of uniform, and reproducibility to apply the SERS substrate. In this paper, we report that Ag nanoparticles are modified after sputtering Ag film on the cicada wing (CW) to preparate the SERS substrate for AgNPs/Ag-20/CW. Compared with Ag-20/CW, the AgNPs/Ag-20/CW has better polarization independence, and the RSD value is 6.1% which represents the excellent uniform of the substrate. The optical properties of SERS substrate are improved by modifying a large number of dense and uniform Ag nanoparticles on the Ag@CW.

Ultrafast nonlinear absorption properties of Ag/Sb2Se3 composite films in the near-infrared region

To explore the nonlinear absorption(NLA) properties of the Sb2Se3 composite system, Ag/Sb2Se3 composite films were prepared by magnetron sputtering at room temperature, and part of the films were annealed under 300 °C. The NLA properties were investigated using femtosecond(fs) Z-scan technology under 800 nm. The results showed that Ag/Sb2Se3 and annealed-Ag/Sb2Se3 composite films exhibited reverse saturated absorption(RSA) and saturated absorption(SA), respectively. The results indicated that annealing could tunable the NLA types of composite films. Furthermore, Ag can strengthen the NLA properties of the Ag/Sb2Se3 composite films compared with the single Sb2Se3. By increasing Ag sputtering power and incident laser energy, the NLA properties of composite films are enhanced. This study provides a new perspective for the application of Ag/Sb2Se3 composite films in optoelectronic devices.

In Situ Sputtering Silver Induction Electrode for Stable and Stretchable Triboelectric Nanogenerators.

Triboelectric nanogenerators (TENG) can convert mechanical energy into electricity and exhibit unique advantages in the field of low-frequency and discrete energy harvesting. However, the interfacial state and stability between the triboelectric layer and electrode layer influence the output and applications of TENG. Herein, an in situ sputtering Ag process for fabricating induction electrodes is proposed to match with TENG. The sputtering Ag process is optimized by a variety of parameters, such as sputtering power, single-cycle time, number of cycles, cycle interval, and vacuum degree. In addition, the chemical state of Ag as a function of air placement is investigated, showing the sputtered Ag has excellent conductivity and stability. Moreover, four kinds of polymers are selected for fabricating TENGs based on the sputtered Ag induction electrodes, i.e., nylon 66, polyimide (PI), fluorinated ethylene propylene (FEP), and polydimethylsiloxane (PDMS), which shows great applicability. Considering the demand of flexible power suppliers, the sputtered Ag is integrated with a PDMS substrate, and shows good adhesion, flexibility, and ductility after severe deformation of the PDMS. Finally, the developed induction electrode processing technology is used in flexible TENG and shows great prospects in self-powered electronics for practical applications.